ZnO has attracted enormous research interest in recent years due to its potential applications for many various applications, such as lasers and light emitting diodes, gas sensors, field emission devices, solar cells, photocatalyst, functional coatings etc. Among many deposition techniques, spray pyrolysis deposition method is well-known as cheap and facile route to prepare ZnO nanostructures. The aim of this work was to study the influence of solution composition on sprayed ZnO nanorods formation process and properties. Two precursor systems were chosen for this study. These are acidic ZnCl2 aqueous solution (pH=3) (1) and basic solution e.g. mixture of ZnCl2 and NH4OH (pH=10) (2). Precursor (2) was dried to white powder at room temperature for one week and while precursor (1) did not fully dry and looked like a sleet even at 70° C. The precursors (1) and (2) were characterized by XRD and FTIR methods. According to XRD, precursor (1) is amorphous and precursor (2) consists of several zinc ammonia complexes. Thermal decomposition was monitored by simultaneous TG-DTA/EGA-FTIR measurements on SetSys-Evo 1600 in the temperature range of 30-800 °C in artificial air (80% Ar+ 20% O2). TG/DTG/DTA curves of (1) indicate a weight loss of 86% in the temperature range of 150 °C and 635 °C. TG/DTA/DTG curves of (2) indicate a weight loss of 76% in the temperature range of 90 °C and 615 °C. The final product of thermal decomposition of (1) and (2) is ZnO. The main evolved gases from (1) are H2O and HCl, whereas the main evolved gases from (2) are H2O, NOx, NH3 and CO2. According to SEM analysis, ZnO rods formation from (2) solutions takes place about 100 °C lower deposition temperatures, than those from acidic solutions. Moreover, the rods obtained from (2) have shown ca. 3 times higher photocatalytic activity for degradation of doxycycline being superhydrophilic (CA=3 ° C), compared to the rods produced from solution (1) (CA=20 °C).